1. Field of the Invention
This invention relates to a light emitting device, more particularly to a highly efficient light emitting device including a light-enhancing layered structure having three inclined faces that are respectively parallel to corresponding symmetrical ones of the crystal planes {11 2 k} of the hexagonal crystal system.
2. Description of the Related Art
Taiwanese patent no. 1236773 discloses a conventional highly efficient light emitting device that can improve its light extraction efficiency by forming a plurality of recesses in a sapphire substrate. The recesses serve to increase internal reflection of light emitted by a light emitting layered structure formed on the sapphire substrate, and are formed using dry etching techniques.